A Chicago Transit Authority Green Line train left the elevated tracks near the Harlem/Lake station in Forest Park, Illinois, at about 3:20 p.m. on September 26, 2026. The incident forced a suspension of Green Line service in the area.
Shuttle buses were deployed to replace the train, and the disruption extended until at least 6:40 p.m., causing several hours of delays for riders.
The Green Line is a primary CTA route that runs from the Loop to Chicago’s western suburbs, and the derailment halted that service temporarily.